Selectorized dumbbells overcome the cost and space obstacles presented by traditional dumbbells. In a selectorized dumbbell, a plurality of weights nest together. The weights provide a stack of nested left weight plates and a stack of nested right weight plates. The left and right stacks of weight plates are separated from one another by a gap.
In a selectorized dumbbell, a handle is inserted into the gap between the left and right stacks of weight plates. A selector is then manipulated to determine how many of the left and right weight plates of the weights are coupled to the left and right ends of the handle. Once the selector is positioned to pick up a selected number of weights, the handle can then be lifted by the user from between the stacks of weight plates. The selected number of weights will rise with the handle to be used in performing various exercises with the dumbbell.
While selectorized dumbbells represent a major advance in exercise equipment, the selectors used to adjust the weight of the dumbbell are mechanical members that must be directly gripped and manipulated by the user. A well known selectorized dumbbell is shown in U.S. Pat. No. 5,769,762, owned by the assignee of this invention. In the dumbbell shown in the 762 patent, the selector comprises a connecting pin that is manually inserted by the user into different locations on the handle to vary the number of weights connected to the handle. Other selectorized dumbbells use other types of mechanical selectors, such as rotatable shafts, knobs, or the like.
With mechanical and user positionable selectors, there is always the possibility that the user might not fully or correctly engage the selector. If this were to occur, one or more weights might inadvertently detach from the handle while the dumbbell is in use. This poses a risk of injury to the user or a risk of damage to the dumbbell. Obviously, this is a disadvantage.
Moreover, many exercises that a typical user might perform require the joint use of a pair of dumbbells. The weight of each dumbbell must be individually set or adjusted. In other words, the user first has to adjust the selector on one of the dumbbells to whatever weight is desired. Then, the user must repeat the procedure for the second dumbbell by adjusting the selector of the second dumbbell. The user must take care to see that the selectors on the two dumbbells are identically positioned to provide the same weight on each dumbbell. Given the small increments of adjusting movement in some known selectors, the user must pay close attention when moving the selector to make sure the proper amount of weight has been selected.
Finally, many people today are quite familiar with electronic devices in which data entry is accomplished by the manipulation of an alpha-numeric keyboard or a numeric keypad or the like. Such data entry devices are found on a host of products such as personal computers, cell phones, television remote controls, etc. Yet, no similar data entry device has been used to adjust the numbers of weights coupled to each end of the handle of a selectorized dumbbell. There is a need in the art to automate and ease the task of adjusting the weight of selectorized dumbbells.